Hydraulic clutch



April 9, 1940. E, A CQRBlN' JR v 2,196,203

HYDRAULICy CLUTCH Filed Sept. 28, 1938 3 Sheets-Sheet 1 e Q Q @l sg EQ Q0 MQ@ :i n- ,slf-m@ m M CCO ..V..-; E @m h 5%! mm my Wi QM MQ @W m m m E w R Q 'V- m N w I o gg Ms N lNvEN'l-'OR ATTORNEY April 9, 1940. E. A. coRBN, JR

' HYDRAULIC CLUTCH Filed Sept. 28, 1938 3 Sheets-Sheet 2 M INVENTOR a @ser 0KB/@JQ BY ,X512 Wwf@ ATTORNEY April 9, 1940- E. A, coRBlN, JR

HYDRAULIC CLUTCH I Filed sept. 2s, 193e 3 Sheets-Sme?I 5 Patented Apr. 9, 1940 v"UNITED 'STATES PAwsxSiry OFFICE.

HYDRAULIC CLUTCH a Elbert A. Corbin, Jr., Lansdowne, Pa., assigner of l one-half to William C. Biddle, Lansdowne,

v Application September 28, 1938, Serial No. 232,061

2 Claims.

My invention relates to a new anduseful hydraulic clutch `or transmission whereby power may be transmitted from a driving to a driven member-without the use of gears and also with- '...5 out the use ofy friction, wet, or dry clutch plates such as are now universally used in automotive vehicles and other engines where power must be transmitted to produce variable speeds in other than electrically driven power plants. l0 In automotive vehicle engines and' the like where friction clutches are employed, the indirect drive is resorted to through lthe medium of gears having certain ratios, and it is necessary to lstart the vehicle moving through one set of gears known as lowv and then to shift as momentum is picked up to a second set of gears and so on into third speed or high, This is 'due to the naturev of Ithe clutch or transmission now in use in which the engagement of the clutch plates of the driving and driven shafts must be accomplishedin degrees or steps as otherwise excessive torque andslippage will occur which would be destructive of the clutch andv other parts of the mechanism. Furthermore, in the conventional friction clutchv there is a certain amount of slippage whenever the clutch plates are allowed to engage regardless of lthe particular speed, all of vwhich"results in limiting the life of the clutch plates. Also, the stepped or graduated increase in speed 4from standstill to maximum is necessitated because'of the impracticability of getting the vehicle tomove at the speed of the engine directly from a standstill position. Y It is therefore the object of my invention to 3,3 produce a hydraulic transmission which employs no friction plates and which is therefore free from the corresponding wear and tear, and which is alsocapable of transmitting power at a gradual and continuously increased rate as opposed .40 to the distinct degrees of speed attained by the change from one set of gears having a definite ratio `to another set of gears having a different denite ratio. My, invention further relates to a hydraulic .15V clutch or vtransmission which can be used as a brake when a vehicle is climbing agrade, but, which, while holding the vehicle against rolling backwardly down hill, also maintains the vehicle in position ready to start up hill whendesired, whereas in conventional vehicles it is necessary to .de-clutch the engine from the vehicle and to .apply the brake to hold. the vehicle against rolling backwards. When the vehicle is again ready to startup hill the releasing of the brake and the u .clutching of the driving to thedriven shaitis a delicate operation which is only performed correctly by a very small number of motorists and in the great majority of cases the vehicle'rolls back two or three feet or more during the movement of the foot from the brake pedal, during the engagement of the clutch, to the accelerator which is admittedly undesirable. Furthermore, the necessary rapid clutch of the driving to the driven shaft causes excessive slippage and corresponding wear and tear on the clutch plates.

My invention still further relates to a clutch or transmission which permits of the use of a simplified 'but adequate mechanism for putting the vehicle in reverse. Also my hydraulic clutch can be operated by the left foot clutch pedal now in use, or it can be connected for automatic operation by the actuation of the accelerator `or engine throttle.

lIn the accompanying drawings:

Fig. 1 represents a horizontal cross section of 20" a hydraulic clutch or transmission embodying my invention, the same being shown in the inoperative position, and also showing the parts in the position in which the vehicle would travel in reverse if lthe clutch mechanism were in its operative position.

Fig. 2 represents a View similar to-Fig. 1 showing the hydraulic clutch mechanism in its full operative position and theother parts in the positionin which the Vehicle would travel forward. v

Fig. 3 represents a section on line 3-3 of Fig. 2.

Fig. 4 represents a section on line 4--4 of Fig. 2.

Referring to the drawings in which .like reference characters indicate like parts, ,B designates the crank shaft of an internal combustion engine or the like, and is provided with the plate 8. The plated is secured by the bolts lli to the plate l2 and also to the adjacent Wall of the casing i4. 40,

, The plate l2 has an inward extension i5 which is provided with suitable 4anti-friction bearings for the end lli of the crank shaft I8 which is provided with the throw 2i). The casing I4 has formed integrallywithin it the piston chambers -22 and 24. From the corresponding walls of the y chambers 22 and 24 extends the hub 26 which is provided with anti-friction bearings 28 and which also extends to form the sleeve 30 which supports thev shaft i8. Also formed integrally within the casing i4 are ther annular chambers 34 and` 36, as well as the extensions lll and l2 which are provided with openings 44 and 4B `forming seats for the Valves 48 and 50. Inter- .mediate the walls of the chambers 34 and '36 55 and the wall oi" the casing I4 is provided the passage 52. The chamber 34 communicates through the annular openings 55 and 44 with the chamber 58 and passage 52, and the chamber 36 communicates through the ports 68 and 46 with the chamber 64 and the passage 52. This communication is established through either of the valve openings 44 or 46 only when either of the valves 48 and 50 is raised above its seat as shown at the top of Fig. 2. The chambers 58 and 64 are formed by the extension casings 86 which are suitably bolted at 58. The annular ports 56 and 5G are normally closed by the annular valves 'IQ and 'I4 which are urged to their closing position by the springs 'I8. Similarly, the valves 48 and 5i) controlling the openings 44 and 48 are normally urged to their closing position by the springs 'I8. Mounted on the throw 28 of the crank shaft I8 are the connecting rods 8U and 82 which carry suitable pistons 84 and 86 which reciprocate in the chambers 22 and 24 respectively. 92 designates a casing which is bolted at 92 to the chassis of the vehicle in any suitable manner. The hub extension 94 of the casing I4 rotates against the bearings 55. 98 designates a suitably packed cover for the casing 9|). |55 designates a stop collar which is suitably secured to the sleeve 3D surrounding the shaft I8 and which serves as an abutment for the adjacent end of the spring |58. In order to support the rear end of the shaft I8 I provide the bearing |82 which is carried by the rib, spider, or web |53 which is integral with or suitably secured to the inner wall of the casing as best seen in Fig. 3. Against the exterior of the stop collar |85 and the bearing |82 is adapted to slide the outer sleeve |54 which carries at its inner end the annular valve |05, which, when in the position shown in Fig. 2 completely closes the passage 52 and obstructs the fiow of fluid therethrough from that half of the casing I4 above the longitudinal axis of the shaft I8 (as viewed in Fig. 2) to the lower half of the casing as viewed in the same ligure. While the vehicle is in motion the valve ring |86 is retained in the closing position shown in Fig. 2 by the spring I 88 by the operating arm IIB. The operating arm IIB is not fully shown in the drawings for the reason that it may assume any desired shape and may terminate in a pedal similar to the conventional clutch pedal or in a lever accessible to the operator of the vehicle or other mechanism.

Referring to Fig. 2 in which the hydraulic clutch is shown in its operative position and in which the vehicle provided with this clutch is in position to move forward, it will be seen that I utilize the sleeve H4 which is keyed at IIB to the shaft I8 and also the sleeve |20 which is key-ed to the shaft |22 at |24. The sleeves ||4 and |28 are vkeyed at I 25 and |28 respectively to the hub |28 which carries the ring gear |38. With the gear |38 in the position shown in Fig. 3 the shaft I8 is integrated with the shaft |22 by the keys |25 and t28 and the shaft |22 will rotate as one with the shaft I8. If it is desired to put the vehicle in reverse the hub |28 is slid in the direction of the arrow in Fig. 2 until it assumes the position shown in Fig. l in which the gear |38 engages the pinion |32 carried on the stud |34. The pinion |32 engages the gear |35 which is keyed to the shaft |22 at |38. The shaft |22 is also provided with any suitable bearings I 4I) and with any desired packing |42. When the hub |28 is moved from the position shown in Fig. 2 to the position shown in Fig. 1, it will be seen that the key |26 is disengaged so that the shaft |22 is no more integrated or compelled to rotate with the shaft I8, and the motion of the shaft |22 due to the gear |30, pinion |32 and gear |34 will be opposite to the direction of the rotation of the shaft I8. The hub |28 is operated by means of any suitable arm or lever |44 which, like the arm IIU which operates the ring valve |06, is also not shown in detail since it can assume any desirable shape or position such as a foot pedal or hand lever accessible to the operator of the mechanism.

The operation is as follows:

With the parts as shown in Fig. 1, that is, with the passage-way 52 open, free communication is established between the opposite halves of the casing I4 on either side of the shaft I8 and the casing I4, as a unit, is free to rotate on its bearings with the rotation of the crank shaft 6. The throw 2D of the shaft I8 remains stationary and the pistons 82 and 86 reciprocate freely in their respective chambers 22 and 24 with each rotation of the casing I4. The casing I4 is filled with any suitable liquid such as oil except that the chamber in which the throw 2U of the shaft I8 revolves is only provided with the oil necessary for lubrication. With the interior of the casing I4 filled with oil the rotation of the casing I4 with the shaft 6 and the reciprocation of the pistons 22 and 24 in their respective chambers simply results in displacing or shifting the oil back and forth from one side of the casing to the other. When the spring |08 has been released to move the annular ring |06 into the position shown in Fig. 2, the free circulation of the liquid in the casing I4 is prevented and the rotation of the casing I4 results in actuating the throw 25 of the shaft I8 and hence rotating the latter. This is due to the fact that the passage-way 52 is closed and the tendency of the piston 84 and 86 to reciprocate and transfer the oil from one side of the casing to the other is prevented. This integrates the casing I4 with the shaft I8 and if the parts are as shown in Fig. 1 the shaft |22 will rotate in the same direction as the shaft I8. Obviously, if by manipulation of the arm III! the ring valve |06 is permitted only partially to obstruct the opening 52, the flow of the oil from one side of the casing to the other is not completely prevented and hence the shaft I8 is rotated at a slower rate than it would be if the passage-way 52 is completely closed. From this it will be seen that the speed of the vehicle can be regulated by the amount of obstruction of the passage-way and that the maximum speed which corresponds to a direct drive between the shaft 6 and the shaft I8 will be attained when the passage-way 52 is completely closed. A vehicle equipped with this hydraulic clutch and climbing up hill needs no brake in the event of stoppage being necessary half way up the hill, since, by proper manipulation of the arm IIB, the passage-way 52 can be obstructed just enough to produce enough pressure against the pistons 84 and 86 to maintain them in the position of tending to turn the shaft I3, but not quite doing so, and since the shaft I8 is connected at its rear end to the driving differential, which is usually carried by the rear axle, it follows that the rear wheels are not permitted to turn either way. When the operator is ready to start up hill again, the passage-way 52 is further obstructed until the pressure within the casing I4 is enough to cause the shaft I8 to rotate. It will benoted that when the piston 7| nular port, the pressure produced by the piston 84 and the suction of the piston 8B serving "to open the annular valve 14 against the tension of the spring 18 as shown at the lower half of Fig. 2 an-d vice versa.

While I have shown two cylinders 22 and 24, it

is obvious that the number of cylinders and pis- I tons employed is not the controlling feature and 15' that the same can be varied at will;

Having thus described my invention, what I claim vas new and desire to secure by Letters Patent is:

l. A hydraulic transmission comprising a driving shaft, an outer casing secured to and rotatable with said shaft, a driven shaft journalled in said casing, piston chambers formed' in said casing, pistons mounted on said driven shaft for `reciprocation in said piston chambers, inner casings surrounding said piston chambers and disposed between them and said outer casing, there beingr openings in the walls of said inner casings,

rvalves for controlling said openings in accordance with the reciprocation of said pistons, there being a central -port for establishing connection between the inner and outer .casings near one piston chamber and the corresponding inner and outer casings neary an opposite piston chamber, a valve for partially or completely closing said center port, and means for controlling said valve.

2. A hydraulic transmission comprising a driving shaft, an outer casing secured toy and rotatable with said shaft, a` driven shaft journalled in said casing, ypiston chambers formed in said casing, pistons mounted on said driven shaft for I reciprocation in said piston chambers, inner casings surrounding said. piston chambers and disposed between them andjsaid outer casing, there being openings in the walls of said inner casings, spring-pressed valves carried by said inner and outer casings for controlling said openings in accordance with the reciprocation of said pistons, there being a central port for establishing connection between the inner and outer casings near one piston chamber and the'corresponding inner and outer casings near an opposite pistonr chamber, a spring-pressed valve slidable on said driven shaftfor partially or completely closing said central port, and means for controlling said valve.

ELBERT A. CORBIN, Jn. 

